PANCREATIC GROWTH AFTER DISTAL SMALL-BOWEL RESECTION IS ALTERED WITH AGING

We have examined age-related changes in the stimulatory effects of dis tal small bowel resection on the growth of the pancreas and on polyami ne biosynthesis. Two groups of male Fischer 344 rats (young; 4-month-o ld, aged; 25-month-old) underwent either 70% distal small bowel resect ion or transection of distal small bowel (control). Rats from each tre atment group of each age were sacrificed on the 10th or 20th postopera tive day (POD), and pancreas was weighed and assayed for DNA, RNA, and protein contents as well as polyamines. We found that young rats with distal small bowel resection exhibited significant increases in pancr eatic weight, RNA, protein, putrescine, and spermine contents on the 1 0th POD, but aged rats that had undergone resection showed only increa sed spermine content. On the 20th POD distal small bowel resection inc reased pancreatic weight, DNA, RNA, and protein as well as spermidine and spermine contents in young rats; aged rats increased pancreatic we ight only. These findings suggest that the trophic responses of the pa ncreas to distal small bowel resection are altered in aged rats, and t hat the polyamine metabolism might be associated with this impaired re sponse.